Desenvolvimento de bebida carbonatada de kefir à base de soro de leite permeado de ultrafiltração

Abstract

Milk ultrafiltration permeate is a solution composed mainly of lactose, salts, non-protein nitrogen, vitamins and water. It is widely generated by the dairy industry due to the use of membrane filtration processes. Ultrafiltration has been used to concentrate milk and whey proteins in order to produce products with a higher protein content. Invariably, the permeate is treated as waste, which can generate environmental damage and costs for the industry. Therefore, the development of new applications for this co-product becomes important. The objective of this study was to evaluate the feasibility of elaborating a fermented beverage by microorganisms from kefir and carbonated grains using ultrafiltration permeated whey. Beverages based on ultrafiltration permeate were prepared, pasteurized, fermented with kefir grains, carbonated and added with natural lemon aroma. The beverage presented a composition of 0% (m/m) of fat, 0.12% (m/m) of protein, 0.49% (m/m) of fixed mineral residue and 90.09% (m/m) of water. The pH of the product varied between 3.42 and 3.47 and the titratable acidity varied between 0.77 and 0.95 g of lactic acid per 100 mL, remaining stable during the 34 days of storage under refrigeration. The beverage color analysis indicated that it presented a light yellow-green color. As for microbiological quality, none of the samples showed coliform counts at 30 or 45 °C, meeting the criteria established by legislation. The counts of mesophilic aerobic bacteria are above those determined by legislation for dairy beverages. The mold and yeast count was between 5.77 and 6.87 Log CFU/mL. The lactic acid bacteria counts ranged from 6.39 to 7.02 Log CFU/mL, and remained viable and active at the same concentration throughout the storage period. The product showed good sensory acceptance during the storage period, with scores above 7 on the nine-point Hedonic Scale. Thus, the use of ultrafiltration permeate for the production of carbonated beverage, fermented with kefir grains, proved to be viable